Before consignment of radioactively contaminated material to a waste disposal facility, for example, a waste landfill site, the contamination on the material must be reduced to below the specified disposal limits of the facility. It is therefore necessary to treat certain materials before disposal in order to ensure that the contamination levels are within the disposal limits.
One known method of treatment includes incineration of the materials. However, a problem has arisen particularly regarding the incineration of used filter media made of or including borosilicate glass fibres contaminated with uranium. Filters having filter media of this type, for example, High Efficiency Particulate Air (HEPA) filters, are used in ventilation systems installed in nuclear fuel processing facilities. The presence of the borosilicate glass fibres results in the encapsulation of uranium during incineration, making it difficult to leach out the uranium from the incinerated product.
It is an object of this invention to provide a method and apparatus for cleaning radioactively contaminated material whereby said material is decontaminated sufficiently to allow safe disposal thereof. It is a particular object of this invention to treat a radioactively contaminated filter medium made of or including glass fibres to render the medium suitable for safe disposal.